中文摘要：

认识农地边际化过程中农户土地利用行为的变化及其对粮食生产的影响,对正确判断中国的粮食生产形势,制订相关政策以确保粮食安全具有重要意义。基于湖北省咸宁市4县1市1区的23个村组、1252个农户家庭的调查数据,对1981年以来农户土地利用行为变化的特征及其对粮食生产的影响进行分析。结果表明：1农户用于粮食生产的劳动力与土地面积明显下降,农户用地方式出现“省工性”变化,劳动力被农机要素替代,农业机械、化学肥料与农药等物质投入显著上升。2主要粮食作物的劳动生产率、土地生产率与商品率分别提高了4.61%、29.69%与50.56%,但区域主要粮食作物的总产量与农户家庭平均粮食占有量却分别下降了10.49%与10.50%,区域粮食安全的保障能力出现弱化。3丘陵山区主要粮食作物的“三率”提高幅度高于平原地区,丘陵山区的水稻总产量与家庭占有量均略有提高,但平原地区却出现了明显下降。产粮重心在空间上出现从平原地区向丘陵山区倾斜的现象。4稳定主要粮食作物的用地规模,促进农户规模经营,提高土地产出效率,是应对农地边际化作用的关键。从事规模化与专业化粮食生产的农区与农户,应成为国家惠农政策与粮食安全政策重点扶持的对象。

英文摘要：

Understanding the change characteristics of farmers＇ behavior in land use and its impact on food production is very useful and necessary for us to clearly judge China＇s food security situation, and has important implications for the formulation of relevant policies to ensure the security of China＇s food. With a stratified random sample method, we surveyed 23 villages of 4 counties, one city and one district in Xianning, Hubei province, and collected1252 farmers＇ behavior data in land use. From the perspective of farmer＇s labor arrangements,allocation of cultivated land resources, patterns of agricultural land use and factors inputs, this paper analyzed the farmers＇ behavior changes in land use during the past 30 years and its impact on food production. The results show：（1） In the process of land use, farm households substantially transfer labor force to non- agricultural areas outside the region, the current main agricultural labors characterized by female, middle- aged and low educational degree labor force, especially in the hills. The labor input per unit of land area dropped significantly. In the adjustment of land use structure, farm households enlarged the operation scale of total land area as well as dryland and reduced the sown area of main food crops（paddy）, especially in the plains. The patterns of farmers＇ arable land use such as field plowing, seeding planting,weeding and harvesting have changed profoundly, and labor forces were replaced by agricultural machinery. As for the other factors of production inputs, farmyard manures were reduced, and NPK chemical fertilizers were gradually replaced by compound fertilizers. The consumption of pesticides increased quickly. More and more families used agricultural service in land use, and the level of agricultural mechanization was improved significantly.（2） In the process of farmer behavior changing, the labor productivity, the land productivity and the grain commodity rate significantly increased by 4.61%, 29.69% and 50.56%, respe